The offense of Driving While Intoxicated is considered a misdemeanor offense. However, even one can be charged with a felony DWI under multiple scenarios:
A misdemeanor DWI can be elevated to a felony offense if a child passenger (under the age of 15) is in the vehicle at the time of the driving.
Also, if you cause an accident resulting in serious bodily injury or death to another person you can be charged with a third-degree or second-degree felony offense. This means you could face up to 20 years in prison. In addition, if the person injured or killed is a police officer, firefighter or some other emergency worker then the punishment range can extend to life or 99 years in prison. This is true even for someone that has never been in trouble a day in their life.
A person that is charged with a DWI and has two prior convictions for that offense can be charged under a felony habitual DWI offender statute. This means you could spend 2-10 years in prison for a third DWI conviction.
If you have previously been convicted of intoxication manslaughter and you are again arrested for a DWI that offense can be enhanced to a third-degree felony.